Electrical insulator.



J. H. ELLIS.

ELECTRICAL INSULATOR.

APPLICATION FILED MAR; 30, 1912.

1,102,252, v Patented Ju 1 y7,1914.

fA EssEs;

JOHN HENRY ELLIS, 0F PRESCOT, ENGLAND.

ELECTRICAL INSULATOR.

Specification of Letters Patent.

Application filed March 30, 1312.

Patented July 7, 1914..

Serial No. 687,331.

T 0 all whom it may concern:

Be it known that I, JOHN HENRY ELLIS, a subject of the King of England,residing at 18 Chester street, Prescot, in the county of Lancaster,England, have invented new and useful Improvements in and Connected withElectrical Insulators, of which the following is a specification.

This invention has reference to electrical insulators, such. forinstance, as those called double-strain insulators, and the like, usedon electric overhead conductor gear, where two or more parts of the gearare connected u by means of the insulator, and are insulated from oneanother, by it.

Generallybut not necessarily always insulators of the kind referred to,are arranged to act in tension.

The object of the invention, is, primarily to provide an insulator ofthis kind, capable of withstanding the stresses or strains to which suchinsulators are subjected, in which the insulation is such that itremains effective and good under all conditions of use.

In the following description, and in the annexed drawing of insulator ofthe kind referred to, the improvements hereunder are comprised; and inthe claiming clauses con cluding the specification, the novelcharacteristics are specified.

It will be assumed that the core or body of the insulator which actuallybears the strain or stress is metallic, say of cylindrical or otherform, having a projecting collar or flange at each end; and that thiscore or body is to be covered with or incloscd in the insulatingmaterial, which may be of a bituminous, or any other suitable orequivalent nature. The covering or enveloping of this body or core withthe insulation effectcd by employing a species of mold, which is adaptedto hold the body or core in posi tion while being covered or inclosed,and by introducingby pressure the. insulating material to and around andover the core or body. The mold is made of larger diameter and size thanthe core or matrix, so that when it is placed in position in the mold, aspace exists between the walls of the mold, and the diti'crent parts ofthe core or body; and this space becomes filled with the insulation whenit is forced under pressure into the mold through and around the body orcore to be inclosed or enveloped. The body or core is .i portcd inposition in the mold while it is being inclcscd or enveloped by theinsulation; which will be introduced either cold or hot, according toits character or nature; but in any case it will be such, that underpressure, it will flow in the manner desired, and as hereinafterdescribed.

One form of insulator according to this invention is illustrated in theaccompany ing drawings, in which Figure 1 is a longitudinal sectionalview of the insulator, the core being shown in elevation. Fig. 2 is anend view of the metallic core or body of the insulator; and Fig. 3 is anoutside elevation of the completed insulator.

The insulator shown is of a form suitable for electrical street or roadoverhead conductor gear or for use for analogous purposes. In thisconstruction, the metallic core or body is made of a tube a-ot which ofis the bore-with radial holes 6 in it, and having afiange or collar. 0at each end, one or both of which is or are fitted on to the tube end orends by a screw thread or threads. Both ends of the tube in the caseshown are threaded; and the collars or flanges c are screwed on to them,and the peripheries of the flanges are grooved orserrated as shown, soas to form a better keying effect of the insulation with them. Thus. inthis construction, there is a longitudinal or axial hole through thebody or core a, and radial holes I) through its wall.

Mica or other suitable insulating washers f are placed on the tube a,before the flanges or collars 0 are screwed on to it: and in the casewhere the insulator is a tension one, as in the case shown, metallicrings or collars h are also passed over it, the center aperture of whichis larger in diameter than the tube a. One of the mica or like washersor rings f comes next each of the metal flanges or collars c, andbetween them and the metal rings or washers h; and in this constructionthese metal rings or washers 71. are flanged in opposite directions. andone flange will come on the outside of each head of the insulator, whilethe other or inner flange will come on the outside of the body portionof the insulation. The outer edge of each of the mica or like insulationwashers f is beveled off as shown, so that its outer edge lies withinthe outer flange of the ring 72, and forms a recess within this flange,between it and the beveled edge of the mica or like ring; and so that,when the insulation material 2' is introduced, and formed around thecore or body, it will also enter this recess, and tend to prevent thecreeping of moisture between these parts, as it furnishes a considerablethickness of insulation there. The purpose of the flange rings orwashers h is to provide metallic parts where the parts of the gear withwhich the insulator is to be connected up with, come. That is to say,the inside of the heads of the insulator will serve as the abutment tothe connecting or coupling parts of the overhead gear in which will beintroduced the rings h, and so provide metallic contact surfaces to takethe friction, wear, and strain.

With regard to the mold, and the manner of applying the insulation tothe core or body of the insulator, if the metal core or body be placedin the mold, it will be seen that it will be held centrally in it by thewashers f and rings h; the outer edges of which will fit and rest in thelarger or head portions of the mold; and the mold is so made that therewill exist between the exterior of the body a, and the interior of thebody portion of the mold, an annular space; while the walls or surfacesof the mold, outside the washers f and rings 0 peripherally and at theends, stand away from these parts, and so provide spaces; and thesespaces are in communication with the annular space outside the body parta, by way of the core hole 03, and the holes 6.

When the body or core has been placed in the mold, the insulation isforced into it by a ram or other forcing means; and it passes or flowsthrough the central bore d of the tube a, and through the radial holesI) in it, into the annular space around the body, which it fills, aswell as-around and over the peripheries and ends of the metal collars orflanges c. The point of introduction of the insulation may be at oneend, or both, or in the middle portion of the mold or any of them; andall the spaces within the mold being in communication, as justdescribed, the How of insulation to all the cavities and spaces by wayof the holes specified, can take place. Thus, when the operation ofintroducing the .insulation is effected, the central and smaller portionof the metal core or body a, as wellas the flanges 0 and washers f onthe peripheries and ends, will be entirely inclosed or enveloped initthe insulationand it will be in one body, without join, and soimpermeable, and immune to the entrance of moisture. After the operationis complete, the mold is taken down or opened, and the completedinsulator re moved.

In the case more particularly described and shown, the bore of thetubular body or core a will, in the completed article, be filled withinsulation, but in some cases, a hole may be formed through theinsulation by introducing a central core in the mold or otherwisesuitablyforming it; and in this case, the inside surface of the tubularportion ofthe body a should be inclosed or covered with the requiredthickness of insulation, similarly to the other parts; this beingeffected by making this central core of less diameter than the internaldiameter of the tube or body part a.

hat I claim is 1. As a new or improved article of manufacture, aninsulator comprising a metal body or core part, having a flanged part atone end of greater diameter than the body; an insulating ring on theinside of said flange; an insulating material (2') covering the outsideof the said body and flange; sub stantially as set forth.

2. As a new or improved article of manufacture, an insulator comprisinga core or body of hard and strong material of tubular form, having aperforated wall, and an external envelop or covering of insulation inwhich the ends, interior and exterior of the body, are all. in onewithout joint; substantially as set forth.

3. An insulator comprising a metal body or core part, having a flangedpart at one end of greater diameter than the body; an insulating ring,as f, on the inside of said flange; insulating material 2' covering theoutside of the said body, with the exception of the parts covered by thesaid insulating ring, and covering also the said flange; substantiallyas set forth.

4. An insulator comprising a metal body or core part, having a flangedpart at one end of greater diameter than the body; an insulating ring.as f, on the inside of said flange; insulating material 2' covering theoutside of the said body, with the exception of the parts covered by thesaid insulating ring, and covering also the said flange; and a metalring on the inside face of the said insulating ring; substantially asset forth.

5. An insulator comprising a core or body a of metal; a flange 0 at eachend of said body. and held thereon by screw threads, insulating rings fin contact with the inner surfaces of the said flanges c. and extendingfrom the said core to beyond the periphery of the said flanges;insulation 2' covering the said body a between the inner parts of theinner faces of the said rings f, and in con tact therewith; and also theperiphery and outer surface of the said flanges, and ends of theinsulator, and said insulation also being in contact with the outer edgeor surface of the said insulating rings; substantially as set forth.

6. An insulator comprising a hollow and perforated core or body a ofmetal; a flange 0 at each end of said body, and held thereon by screwthreads, insulating rings f in con tact with the inner surfaces of thesaid flanges c, and extending from the said core to beyond the peripheryof the said flanges; insulation i covering the internal surface of thebody, and extending through the perforations thereof, and covering thesaid body a between the inner parts of the inner faces of the said ringsf, and formed in contact with the said faces. and also arranged incontact with the periphery and outer surfaces of the said flanges, andends of the in- 10 sulator; and said insulation also being in contactWith the outer edge or surface of the said insulating rings;substantiallyas set forth.

In testimony whereof I have signed my name to this specification in thepresence of 15 two subscribing Witnesses.

JOHN HENRY ELLIS. Witnesses:

SOMERVILLE GoonALL, HAROLD HOLMES.

